Long-term (2001–2013) observations of water-soluble dicarboxylic acids and related compounds over the western North Pacific: trends, seasonality and source apportionment

Boreddy, Suresh K. R.; Kawamura, Kimitaka; Tachibana, Eri

doi:10.1038/s41598-017-08745-w

Cited by 34 publications

(40 citation statements)

References 93 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Their influence and contribution will be discussed in the following sections. The OC/EC ratios found in this study for the KV were similar to other sites in South Asia, like Lumbini (5.16 ± 2.09, 2.41-10.03; Wan et al, 2017), Delhi (5.86 ± 0.99, 2.9-9.2; Bisht et al, 2015), and Lahore (3.9 ± 1.6, 1.5-7.2; Alam et al, 2014).…”

Section: Major Ions Oc and Ecsupporting

confidence: 88%

“…Field blanks (one blank filter each month) were also collected, briefly putting a filter onto the instrument without drawing air to assess potential contamination. There may be positive and negative artifacts during the sample handling/conditioning due to the adsorption/evaporation processes of organic aerosols (Li et al, 2018;Boreddy et al, 2017;Oanh et al, 2016). In a comparable study, Ding et al (2013) reported the positive artifacts for OC and organic tracers were 10 %-20 % and up to 16 %, respectively.…”

Section: Sample Collectionmentioning

confidence: 89%

“…8). Budisulistiorini et al (2017) investigated that the concentrations of B-SOA could significantly increase as the aerosol acidity enhances based on the laboratory simulations and field observations. The significant influence of I-SOA by SO 2− 4 might be explained by the concerted nucleophilic addition to the key intermediates in the gas phase (e.g., isoprene epoxydiols), which is the rate-determining step in SOA formation (Xu et al, 2015;Li et al, 2018).…”

Section: Isoprene Soa Tracersmentioning

confidence: 99%

See 2 more Smart Citations

Molecular characterization of organic aerosols in the Kathmandu Valley, Nepal: insights into primary and secondary sources

et al. 2019

Self Cite

View full text Add to dashboard Cite

Abstract. Organic atmospheric aerosols in the Hindu Kush–Himalayas–Tibetan Plateau region are still poorly characterized. To better understand the chemical characteristics and sources of organic aerosols in the foothill region of the central Himalaya, the atmospheric aerosol samples were collected in Bode, a suburban site of the Kathmandu Valley (KV) over a 1-year period from April 2013 to April 2014. Various molecular tracers from specific sources of primary organic aerosols (POAs) and secondary organic aerosols (SOAs) were determined. Tracer-based estimation methods were employed to apportion contributions from each source. The concentrations of organic carbon (OC) and elemental carbon (EC) increased during winter with a maximum monthly average in January. Levoglucosan (a molecular tracer for biomass burning, BB) was observed as the dominant species among all the analyzed organic tracers and its annual average concentration was 788±685 ng m−3 (ranging from 58.8 to 3079 ng m−3). Isoprene-SOA (I-SOA) represented a high concentration among biogenic-SOA tracers. For the seasonality, anhydrosugars, phenolic compounds, resin acid, and aromatic SOA tracer showed similar seasonal variations with OC and EC while monosaccharides, sugar alcohols, and I-SOA tracers showed lower levels during winter. BB contributed a significant fraction to OC, averaging 24.9 %±10.4 % during the whole year, and up to 36.3 %±10.4 % in the post-monsoon season. On an annual average basis, anthropogenic toluene-derived secondary OC accounted for 8.8 % and biogenic secondary OC contributed 6.2 % to total OC. The annual contribution of fungal spores to OC was 3.2 % with a maximum during the monsoon season (5.9 %). For plant debris, it accounted for 1.4 % of OC during the monsoon. Therefore, OC is mainly associated with BB and other anthropogenic activity in the KV. Our findings are conducive to designing effective measures to mitigate the heavy air pollution and its impacts in the KV and surrounding area.

show abstract

Section: Major Ions Oc and Ecsupporting

confidence: 88%

Section: Sample Collectionmentioning

confidence: 89%

Section: Isoprene Soa Tracersmentioning

confidence: 99%

See 1 more Smart Citation

Molecular characterization of organic aerosols in the Kathmandu Valley, Nepal: insights into primary and secondary sources

et al. 2019

Self Cite

View full text Add to dashboard Cite

show abstract

“…4b). This result suggests an additional source of organic matter (completely independent of sea salt production and wind speed) which is evidenced by the higher MSA − / nss-SO 2− 4 mass ratios and higher concentrations of azelaic acid (Boreddy et al, 2017) during summer and autumn. MSA − / nss-SO 2− 4 mass ratios have been suggested as an indicator for the relative contribution of oceanic dimethyl sulfide (DMS) vs. anthropogenic sources to sulfate (Gondwe et al, 2004;Savoie and Prospero, 1989).…”

Section: Monthly/seasonal Variationsmentioning

confidence: 69%

Long-term (2001–2012) trends of carbonaceous aerosols from a remote island in the western North Pacific: an outflow region of Asian pollutants

2018

Self Cite

View full text Add to dashboard Cite

Abstract. The present study reports on long-term trends of carbonaceous aerosols in total suspended particulate (TSP) samples collected at Chichijima in the western North Pacific during [2001][2002][2003][2004][2005][2006][2007][2008][2009][2010][2011][2012]. Seasonal variations of elemental carbon (EC), organic carbon (OC), and water-soluble organic carbon (WSOC) concentrations showed maxima in winter to spring and minima in summer. These seasonal differences in the concentrations of carbonaceous aerosols were associated with the outflows of polluted air masses from East Asia, which are clearly distinguishable from pristine air masses from the central Pacific. The higher concentrations of carbonaceous aerosols during winter to spring are associated with long-range atmospheric transport of East Asian continental polluted air masses, whereas lower concentrations may be due to pristine air masses from the central Pacific in summer. The annual trends of OC / EC (+0.46 % yr −1 ), WSOC (+0.18 % yr −1 ) and WSOC / OC (+0.08 % yr −1 ) showed significant (p < 0.05) increases during the period of 2001-2012, suggesting that photochemical formation of WSOC and its contributions to secondary organic aerosols (SOAs) have increased over the western North Pacific via long-range atmospheric transport. We found a significant increase (+0.33 % yr −1 ) in nss-K + / EC ratios, demonstrating that concentrations of biomass-burning-derived carbonaceous aerosols have increased, while those of primary fossilfuel-derived aerosols have decreased over the western North Pacific. Further, secondary biogenic emissions are also important over the western North Pacific as inferred from a significant increase (+0.14 % yr −1 ) in the concentrations of methanesulfonate (MSA − , a tracer for biogenic sources). This point was further supported by a moderate correlation (r = 0.40) between WSOC and MSA − . We also found a significant increase in OC / TC (total carbon) and WSOC / TC ratios, further suggesting that photochemical formation of WSOC and its contributions to SOAs have increased over the western North Pacific during 2001-2012 via long-range atmospheric transport from East Asia.

show abstract

“…Organosulfates (OSs), commonly formed via the interaction between VOC precursors and acidic sulfate seed particles, could be a potential source of "missing SOA" in current atmospheric models . OSs have been observed in various ambient atmospheres, including urban, rural, suburban, forest, and remote environments Meade et al, 2016;Stone et al, 2012;Riva et al, 2015;Brüggemann et al, 2017), which could represent 2-30 % of OA (Hawkins et al, 2010;Stone et al, 2012;Frossard et al, 2011;Tolocka and Turpin, 2012;Surratt et al, 2008;Liao et al, 2015).…”

mentioning

confidence: 99%

Responses to Referee 1

Hu¹

2018

Preprint

View full text Add to dashboard Cite

Organosulfates (OSs) with ambiguous formation mechanisms are a potential source of "missing secondary organic aerosol (SOA)" in current atmospheric models. In this study, we chemically characterized OSs and nitrooxy-OSs (NOSs) formed under the influence of biogenic emissions and anthropogenic pollutants (e.g., NO x , SO 2− 4 ) in summer in Beijing. An ultrahigh-resolution mass spectrometer equipped with an electrospray ionization source was applied to examine the overall molecular composition of S-containing organics. The number and intensities of Scontaining organics, the majority of which could be assigned as OSs and NOSs, increased significantly during pollution episodes, which indicated their importance for SOA accumulation. To further investigate the distribution and formation of OSs and NOSs, high-performance liquid chromatography coupled with mass spectrometry was employed to quantify 10 OSs and 3 NOS species. The total concentrations of quantified OSs and NOSs were 41.4 and 13.8 ng m −3 , respectively. Glycolic acid sulfate was the most abundant species among all the quantified species, followed by monoterpene NOSs (C 10 H 16 NO 7 S − ). The total concentration of three isoprene OSs was 14.8 ng m −3 and the isoprene OSs formed via the HO 2 channel were higher than those formed via the NO / NO 2 channel. The OS concentration coincided with the increase in acidic sulfate aerosols, aerosol acidity, and liquid water content (LWC), indicating the acid-catalyzed aqueousphase formation of OSs in the presence of acidic sulfate aerosols. When sulfate dominated the accumulation of secondary inorganic aerosols (SIAs; sulfate, nitrate, and ammonium; SO 2− 4

show abstract

Long-term (2001–2013) observations of water-soluble dicarboxylic acids and related compounds over the western North Pacific: trends, seasonality and source apportionment

Cited by 34 publications

References 93 publications

Molecular characterization of organic aerosols in the Kathmandu Valley, Nepal: insights into primary and secondary sources

Molecular characterization of organic aerosols in the Kathmandu Valley, Nepal: insights into primary and secondary sources

Long-term (2001–2012) trends of carbonaceous aerosols from a remote island in the western North Pacific: an outflow region of Asian pollutants

Responses to Referee 1

Contact Info

Product

Resources

About